The common adjustable resistance is mainly by changing the length of the resistance access circuit to change the resistance value, it can gradually change the current in the electrical appliances and it can also gradually change the voltage of the electrical appliances in series and it can also play the role of protecting electrical appliances. In the experiment, it also plays the role of obtaining multiple sets of values.

The failure rate of variable resistor is obviously higher than that of ordinary resistor because of its structure and use. Variable-signal resistors are commonly used in small-signal circuits, and in a few cases, such as vacuum tube amplifiers, large-signal variable-signal resistors are also used.